Punnett square

In this punnett square, "G" is a dominant allele present in most human beings. The recessive, "g", represents the allele responsible for the special genetic abilities that allow people to survive Progenitor virus infection and gain superhuman characteristics. The letter "g" is taken from an interview with one of the Capcom developers of Resident Evil 2, who said that the G-Virus project and (what would become) Project Wesker had parallels in that they were to engineer the next stage in human evolution. As this phenotype is rare (1:100,000,000 chance of a person being homozygous), it is no doubt a recessive trait.

First generation

In this instance, one of the parents (the father) was heterozygous - he had both the dominant and recessive alleles. The other (the mother) is homozygous dominant - she only had dominant alleles. As such, there was a 50% chance of having a baby who was heterozygous (therefore being a carrier of the recessive allele, which is not active in their own bodies), and another 50% chance of the baby being homozygous dominant (and therefore lacking the recessive allele altogether).

G (paternal)

g (paternal)

G (maternal)

GG (unaffected)

Gg (carrier)

G (maternal)

GG (unaffected)

Gg (carrier)

In this alternate chart, both the mother and father are heterozygous. This gives us:

25% - Homozygous dominant

50% - Heterozygous

25% - Homozygous recessive

If we were to simplify the genetic factors it takes to have one of these special children (assuming that it all depends on this one gene rather than a number of them), the parents of Albert and Alex Wesker only had a 25% chance of having such children.

G (paternal)

g (paternal)

G (maternal)

GG (unaffected)

Gg (carrier)

g (maternal)

Gg (carrier)

gg (affected)

Second generation

Here's how we get Jake. The father (Albert) is homozygous recessive. His partner on the other hand (I have concluded that it's very unlikely for him to meet a woman who was also homozygous recessive - Umbrella had a thing for hunting down these people and turning them into Tyrants). Their chances are so:

50% - Homozygous recessive

50% - Heterozygous

g (paternal)

g (paternal)

G (maternal)

Gg (carrier)

Gg (carrier)

g (maternal)

gg (affected)

gg (affected)

If Wesker had a children with a woman who did have all the markers, it would of course be a 100% guarantee.